News aggregator

Yesterday, we deployed the seismic streamer and source of the R/V Langseth in record time - its no small feat to put 8 km (~5 miles) of streamer plus other equipment in the water behind a ship. The streamer is filled with pressure sensors that will record sound waves that have traveled into the earth and bounced off geological features, like faults, sedimentary layers, and ancient lava flows. It is unwound from a gigantic spool on the back of the vessel. As it leaves the ship, we festoon it with a variety of important devices, like “birds” that control the depth of the streamer, “streamer recovery devices” that are air bags that deploy and float the streamer to the surface if it gets too deep, and acoustic navigation units that are used to help determine the position of the streamer beneath the ocean surface. A tail buoy is located at the end of the streamer to help with positioning and alert others of the presence of the streamer, and a float is at the front to further control the depth of the streamer. We also check that everything is working while we’re putting it into the water. We deployed all 8 km in just 7 hours, and were rewarded with a rainbow and spectacular sunset as the last bits of equipment went off the stern. We also deployed the seismic source, which consists of air guns suspended below four snake-like black floats. Now that all the kit is in the water, we are happily collecting data. Its a very good moment when the seismic data begins to come in...Donna Shillington aboard the R/V LangsethThe top of the streamer reels. We are unspooling seismic streamer from the reel on the right. (Photo: Jenna Hill)Looking towards the stern across the streamer reel (Photo: Derek Sawyer)Matt, Sasha and Carlos attach a bird to the streamerThe streamer entering the water behind the ship with a birdKara fetches a bird to place on the streamerMatt and Robert monitor the deployment operation from the main lab.A rainbow hovers over Jenna and Ben with the final bit of streamer (Photo: Derek Sawyer)

September 18th, 20141625I was awoken early this morning, after only a few hours of sleep, by some unknown portion of my subconscious and was struck by a thought concerning the unique nature of performing science at sea. The ocean, as a scientific laboratory, forms a constant connection with those who venture into it that is experienced by few, if any, terrestrial experimentalists. During my 12-hour watch, my mind is clearly engaged by the science that we are performing. When is the next instrument being deployed? What needs to be done to be ready for it? Will we survey this instrument once it rests on the seafloor? These are just a few examples of the many questions that cross not only my mind, but the minds of my peers as well. More interestingly, however, I also find that I am acutely aware of changes to my environment, which readily defy alterations in our scientific progress, even as I lay semi-conscious in my bunk. The temporal spacing between the response of the 12hz Echosounder pinging against the hull informs me of any relative change in depth from the last time I was awake. The direction and intensity of the ship’s sway can tell me about our heading and/or a change in weather conditions. A variation in the output frequency of the engine’s constant drone provides me with our current speed and suggests what kind of scientific activity the other watch might be performing one deck above my head. It the result of these types of observations that those aboard these floating beasts that operate 24-hours a day are constantly engaged in their environment, whether or not they desire to be. Anyways, perhaps this helps orient those who have never been to sea for an extended period or recalls reflection for those who have ventured out into the wild blue yonder previously, either way I felt it was an interesting thought worth sharing.Currently, the R/V Endeavor is a little over halfway through its transit back to the end of Line 2. Along the way, we surveyed OBS Sites 210 and 211 to accurately locate each device on the seafloor which will assist with our recovery. Once we reach the eastern end of Line 2, before starting our recovery operations, we will perform a rosette test. However, the event that all the scientific party is looking forward to is passing by the R/V Langseth sometime early evening and waving ‘hello’ to our scientific comrades.Till next time,Dylan Meyer aboard the R/V EndeavorOne of the crew, Chris, noticed this awesome moth that landed on deck yesterday. A clear sign that we were close to shore (Photo Credit: Dylan Meyer)After passing through a heavy squall, we were rewarded with a full rainbow! (Photo Credit: Dylan Meyer)

September 17, 2014We are moving right along with our OBS deployments. We have finished deploying along line 3 and line 2. The R/V Langseth is now on its way to start shooting line 2. Next we are heading back for the recovery of line 2 before starting to deploy at line 4. The seas have been fairly calm, making for easy deployments and smooth sailing!

September 16th, 20142142At 0630 on September 15th, after a successful CHIRP survey, rosette test, and styrocast, our team released the first OBS, allowing it to fall 4100 meters to the seafloor. Our first deployment was of an OBS from WHOI, pictured below, and it was followed a couple hours later by an OBS instrument from SIO. This method was adopted to get the members of the watch acclimated to the process of preparing and launching each of these devices. Now, approximately 39 hours later, both watches have fallen into a rhythm, each person comprehending how to efficiently setup and deploy both types of instrument. As a result of our efforts, we are currently ahead of our original schedule! We are currently 16 instruments away from completing our first deployment campaign and are looking forward to beginning to recover our instruments for redeployment. Also, everyone on board to excited to hear that the R/V Langseth has left the dock early on the 16th and is in transit to begin their multi-channel seismic (MCS) surveys!Until next time,Dylan Meyer aboard the R/V EndeavorI would like to thank science (and pressure) for helping us shrink 15 styrofoam cups to approximately a quarter of their original size! (Photo Credit: Dylan Meyer)A WHOI OBS being prepared for deployment at night. The SIO OBS lays ready for later deployment just off to the left. (Photo Credit: Dylan Meyer)An OBS from WHOI about to be released. (Photo Credit: Dylan Meyer)A small rain squall on the horizon is a common occurrence out here. Personally, I find them very refreshing! (Photo Credit: Dylan Meyer)Sunset on September, 16th. I swear this photo is unedited. (Photo Credit: Dylan Meyer)

This morning, the R/V Langseth left port in Norfolk, passing saluting gantry cranes, container ships, and naval vessels on her way out to open waters. The sun is shining and the seas are calm – perfect weather for adjusting to life at sea and getting our collective sea legs. The R/V Langseth tied up at Lambert Point port in NorfolkWe will steam for ~24 hours to the eastern edge of our study area, where we will deploy our sound source and an 8-km-long streamer filled with pressure sensors. Over the next 35 days, we hope to use this seismic equipment to image everything from the base of the crust and deep magmatic intrusions related to the breakup of Pangea and opening of the Atlantic ocean to recent, large landslides along the east coast. We will report often!Passing container ship...Cranes waving to us...Air craft carriers in NorfolkMatt Hornbach and Derek Sawyer rocking lifejackets at the first Fire and Emergency DrillThe science party of MGL1408Donna Shillington aboard the R/V Marcus Langseth

Over the last three days Celia and I (both geophysics graduate students at Columbia University – Lamont-Doherty Earth Observatory) have been servicing ENAM’s three land-based broadband seismometers that sit on the Outer Banks of North Carolina. These seismometers, installed in May of this year, represent a critical extension of ENAM’s ocean work as they expand the project’s scientific footprint across the western expression of the Eastern North American Margin magnetic anomaly. This feature is one of ENAM’s key scientific targets as it is believed to be intimately tied to the complex rifting history of the Atlantic Ocean. Map showing the locations of existing USArray seismic stations (white), ENAM offshore seismic stations (yellow), and ENAM onshore seismic stations (red).For our part, the goals for this service run were simple: 1) Safely retrieve the previously recorded data from the seismometers and 2) Check to make sure the instruments have been and currently are running well. After spending a few days working in the sun and sand we are cautiously happy to report that we were successful on both fronts! First let’s talk about data. Station CHPH located near Cape Hatteras Middle School. The solar panel sits on the right and the computer and seismic instrument sit buried beneath the sand on the left. Their location is marked by the line of logs.These instruments were installed in May 2014 and have been sitting quietly, buried beneath the sand recording ground motions from distant earthquakes ever since. Amongst the treasure trove of data that we retrieved from the instruments are gorgeous records of both the Mw 6.9 Chiapas, Mexico event and of the recent Mw 6.0 Napa Valley earthquake, just to name a few. Scientists will utilize traces of events such like these recorded at these stations to image the subsurface along the North Carolina coast with the aim to reveal the tectonic and deformational history of the region. Seismic records from the recent Mw 6.0 Napa Valley earthquake (left) recorded on ENAM station FFMS (located at First Flight Middle School) and the Mw 6.9 Chiapas, Mexico earthquake (right) recorded on station CHPH (located at Cape Hatteras Middle School).With the data safely retrieved and stored on backup hard drives, we next moved onto checking on the instruments themselves or as we call it, their “state of health” (SOH). The term SOH includes a variety of checks including the temperature of the digitizer (the computer that interacts with the seismometer), the accuracy of the clock used to keep time for the seismometer, the voltages of the batteries that power the instrument and the computer, … By looking at the SOH we make sure that the entire package from the instrument to the computer to the solar panel (used to charge the battery) is performing adequately and that all components are successfully interacting with each other. Natalie (left) and Celia (right) stand proudly in front of recently serviced seismic stations ECHS (located at East Carteret High School) and FFMS (located at First Flight Middle School).With the data collected and health of the stations verified, it’s time to leave the seismometers to collect data silently by themselves for another few months. More students and scientists will come to check on them again and retrieve their records this winter. With such an active and dynamic world around us, who knows what geophysical treasures will be hidden amongst the data that will be collected then!- Natalie Accardo, Columbia University - LDEO

September 15, 2014Testing one, two, three! We successfully completed a Rosette test of the Scripps acoustic transducers at 4000 meters water depth. We wanted to be sure we could talk to the ocean bottom seismometers once deployed to the bottom of the Atlantic where the pressure is around 40 MPa and the temperature at about 4 °C. The test went smoothly, and now we are ready to deploy! While we were at it, we had a little fun with Styrofoam cups sending them down as well with messages and pictures making styrocasts.

September 14, 2014Science! At about 20:30 Eastern Time on September 13 we reached our first survey site off the coast of Virginia. While we’re excited to start deploying ocean bottom seismometers, we know that there might be some coral in the area. We don’t want to disturb any wildlife and therefore want to avoid placing an ocean bottom seismometer on any coral. We used 3.5 KHz sound waves to penetrate the subsurface and see what the seafloor looked like in order to find a safe place for the OBS. We surveyed the desired area of deployment and 500 meters in any direction from that location. Overall we surveyed 3 separate locations finishing up about three in morning.

The science party discussing the recording of the survey. (Photo Credit: Gary Linkevich)Kate watching the response from the 3.5 KHz chirp. (Photo Credit: Gary Linkevich)Gary, Brandon and Harm looking at the record from the 3.5 KHz chirp survey

It’s a beautiful, sunny day in North Kingstown, RI and the R/V Endeavor bustled with activity as we made the final preparations for our 38-hour transit to Cape Hatteras. The past two days have been a blur of science meetings, last minute purchases and preparations, and forced suppression of my excitement to be onboard another research cruise. I now stand on the observation deck above the bridge, calmed by the brisk sea breeze rushing through my hair, ready for the tasks required of me in the month to come.

The R/V Endeavor at dock from astern. The OBSs have been loaded onto the fantail. (Photo Credit: Dylan Meyer)Initial science party meeting while still at the dock. (Photo Credit: Dylan Meyer)On the observation deck after getting under way. (Photo Credit: Jennifer Harding)Okay, enough of the fluffy mumbo-jumbo. Let’s get to the good stuff. For those of you who haven’t yet read through the information on the Eastern North American Margin Community Seismic Experiment (ENAM CSE), may we never have to write out that acronym in full again, here’s a summary of our research goals on the R/V Endeavor. Over the next 32 days at sea (or less, if things go well), we have four main tasks:

- Perform a survey of the seafloor near three drop sites that are within an essential fish habitat - habitat area of particular concern (EFH-HAPC) off Cape Hatteras to assure proper placement of our equipment. - Test the acoustic release mechanisms for the Ocean Bottom Seismometer (OBS) devices from Scripps Institution of Oceanography (SIO) and the Woods Hole Oceanographic Institution (WHOI), to assure that we can release the OBSs from the seafloor during the recovery process. - Deploy and recover each of the 47 OBSs twice along the four multi-channel seismic (MCS) lines that will be shot by the R/V Langseth. - Perform all the above operations in an efficient and safe manner.

The figure below shows the deployment stations for each of the OBSs and the MCS lines that will be run on the R/V Langseth after deployment.

Bathymetric/topographic map of the region around Cape Hatteras with MCS lines drawn in blue and OBS deployment stations as pink dotsThe expanse of this experiment is absolutely incredible, and I highly suggest that you visit the “About” portion of this blog site as well as the GeoPrisms website:

http://www.geoprisms.org/enam.html

for additional information on the broader scientific goals of the ENAM CSE as well as specifics about the other branches of the experimental plan (MCS array, terrestrial seismic, long-period OBS).

Our scientific party consists of twelve people (2 research scientists, 6 graduate students, and 4 OBS technicians) from institutions spread across the US:

Research scientists and graduate students of the scientific party aboard the R/V Endeavor. From left to right - Pamela Moyer, Jennifer Harding, Afshin Aghayan, Dylan Meyer, Kathryn Volk, Brandon Dugan, Harm van Avendonk, and Gary Linkevich. (Photo Credit: Gary Linkevich) The scientific party (partial group photo above), assisted by the magnificent crew of the R/V Endeavor, will hopefully start our OBS deployment by Sept. 16th on lines 2 and 3, completing enough of the deployments on Line 2 such that the R/V Langseth can begin shooting as soon as they are on station and their equipment is deployed. From that point, we will recover all the OBSs and redeploy them along lines 1, 4a, and 4b in time for the R/V Langseth to begin shooting those MCS lines sometime on Sept. 30th. The OBSs will then be recovered and the R/V Endeavour will steam back to Quonset Point, arriving some time on or before Oct. 13th (knock on wood).

Before any science could commence, however, we all participated in a mandatory safety lecture and ship orientation. We tried out the “Gumby” Immersion Suits (pictured below), learned the essential emergency procedures, and were introduced to the myriad of safety equipment available on the R/V Endeavor. I have no doubts that the University of Rhode Island has provided us with a superbly safe working and living environment.

Testing out the "Gumby" suits during the safety orientation after getting under way. (Photo Credit: Gary Linkevich)We’ve started our 12-hours on/off shift schedule now and I can already start to feel people falling into a routine. As we steam ahead with the wind from astern and following seas, the scientists on watch make preparations, calculations, and estimations aimed at improving our efficiency, while those off watch read, rest, and relax in anticipation of their next watch. The sun is shining, the seas are calm, and everyone is excited to get to work.

An artist’s illustration of the tree-dwelling mammal Xianshou songae (illustration by Zhao Chuang). The discovery of three new Jurassic species suggests that mammals evolved earlier and diversified more rapidly than previously thought.

The Northstar 1 brine injection well in Youngstown, Ohio, was closed after a series of earthquakes. Lamont-Doherty researchers later linked the tremors to the injection of waste fracking fluid underground.